Cassidy will likely have the reigns for the remainder of the season and, depending on the results, he may be offered the position permentaly in the off season. Should it not end well, anticipate that they will go through the process of looking outside the organization. The folks who will be tasked with leading that search may also change by that time should the season not end well.
If that is the case, it makes you wonder where they've set the bar for him. If they fail to make the playoffs, is that on Cassidy or are there are other things they would be evaluating him on? If you're Cassidy, do you accept the position under the constraint to make the playoffs knowing what you know about the team and their current position? I guess it is how the club defines the season "ending well" because I can't imagine ANY coach coming in at this point and believing that a playoff appearance could be unquestioningly be achieved.